A projection system typically includes a light source, one or more image forming components or imagers, projection optics, and potentially a screen. Often, imagers used in projection systems are polarization-rotating, image-forming devices, such as liquid crystal display imagers, which operate by rotating the polarization of the light to produce an image corresponding to digital video signals. Imagers used in projection systems typically rely on polarizers to separate light into a pair of orthogonal polarization states (e.g., s-polarization and p-polarization) before the light may be imaged. Therefore, projection systems will also generally include a polarizing beam splitter (PBS) to serve this purpose.
Due to new demands on PBSs, in part due to their new uses in applications such as, e.g., three-dimensional projection or ultra-compact projection systems that have relatively high light output, a number of new issues have arisen. The present application provides articles and systems that address such issues.